Roping through portals

[MarkB]

I rather like the way it's handled in the Stargate TV series.

A Stargate is a flat, shimmering plane through which one steps to emerge from another gate. It's one-way, at least for solid objects, but an object does not begin its journey from one gate to another until it has passed completely through the gate - defined, simply, as the gate's surface no longer having any obstruction penetrating it.

Until then, an object that has passed partially through the gate is held in a timeless, spaceless 'vestibule' just beyond the gate's surface - a 'pocket plane' in D&D parlance.

So if you send someone through the gate tied to a rope, and haul them back five minutes later, they won't be able to tell you what's on the other side, because they never got there. In fact, as far as they're concerned, they didn't have time to go anywhere - to their perception, you hauled them back out the moment they stepped across the threshold.

It's a fairly neat solution to making a one-way gate without having to worry too much about issues like "what if I send someone through on a rope?" or "what happens to the blood trying to flow back across the threshold within my veins as I step through?"

The series also has a few examples of other 'portal' standards - there's the 'ring transporter', a short-range teleporter that drops a stack of rings around a designated transport zone, forming a vertical cylinder, and then teleports anything inside the cylinder. That one will sever anything that's partially within the zone of effect when it activates.

There's also the 'alternate reality mirror' - a seemingly-ordinary mirror, which is in fact a window to parallel worlds. The moment you touch the mirror, you cross over to the parallel world without any sensation of physical movement, and are now peering back through the mirror to your former reality. That one appears deliberately keyed to living beings, so a thrown rope would not cross over. What would happen if a tethered character crossed over is pure speculation, but most likely they'd either leave the rope behind or take its entire length with them.

 

[haakon1]

The only thing I'd add to the Stargate portal commentary is that when the gate closes, it disintegrates anything that was still at the event horizon, including both the back of someone's head in one episode, and a rope in another.

The rope was being used by the first Earthman to explore the Stargate. When it shut down unexpectedly, it left his friends holding the loose end of the rope.

 

[Janx]

2 way portals are handled quite simply, it's just like passing through a door.

1 way portals are trickier.

The star gate buffer works as one explanation. Otherwise, as you are passing through the gate, if any part of you (like an arm) swings back, you'd be in conflict with the 1-way behavior.

What this also touches on are:
what really happens when a person/rope starts going into a Sphere of Anhilation

Because if it it absolutely destroyed the submerged matter right away, the person would know with the end of the first body part they put in. It would hurt like heck, and they'd be loosing blood quickly into sphere.

A rope would also act wierd, because it would cease to have any weight on it at the surface of the Sphere. Anybody who's actually handled rope knows what it feels like with a load. In fact, the rope, suddenly unencumbered by any weight on the end, would act quite loose, possibly even curling up from the sphere.

Therefore, the DM needs to decide, much like original questions, what happens, so he can describe the clues as to what it is. If you're hoping to nail a PC, you going to have to make it a little safer initially.

 

[Man in the Funny Hat]

While I basically use Umbran's approach the results can nonetheless differ from one to the next as well as depend on precisely how things are being attempted.

For example, if one person tied a rope to himself, had another hold the other end of it and stepped through I might rule in one of a couple of different ways. It would depend upon how I thought the wizard who created the portal wanted it to work - which is to say how _I_ wanted it to work in this specific situation. Unless this were part of a reasonably extensive, unified network of portals as a DM I have every motivation to introduce a wide variety of functionality; every portal is going to be unique in some fashion or other.

 

[Lanefan]

While I basically use Umbran's approach the results can nonetheless differ from one to the next as well as depend on precisely how things are being attempted.

For example, if one person tied a rope to himself, had another hold the other end of it and stepped through I might rule in one of a couple of different ways. It would depend upon how I thought the wizard who created the portal wanted it to work - which is to say how _I_ wanted it to work in this specific situation. Unless this were part of a reasonably extensive, unified network of portals as a DM I have every motivation to introduce a wide variety of functionality; every portal is going to be unique in some fashion or other.

Ayup.

Would have just given a thumbs-up but it tells me I need to spread the love around...

Lan-"as you walk through the shimmering wall, the rope falls off"-efan

 

[Ashtagon]

Two-way portals allow things to pass freely across the boundary. They may or may not have some kind of sensory screen that stops you sensing (sight/sound) what is on the other side (which may or may not block senses in one direction only), and a hostile environment might destroy any probes pushed through.

One way portals stop people and objects being pulled back. However, they have a "nullspace" region in them, a few inches deep, which is generally resistant to passage. As long as you haven't penetrated the nullspace region, you can pull back. This of it something like a very shallow airlock. You can enter and leave the nullspace from the starting region freely, but can't enter the region beyond the nullspace. Once you are fully in the nullspace, you can only continue going forwards (or stay in the nullspace). A rope threaded through such a portal would effectively prevent an explorer at the leading end of the rope from passing the far end of the portal, since the first part of the "airlock" wouldn't have been allowed to close.

Just like two-way portals, one-way portals may or may not block senses, in one or both directions.

 

[Saeviomagy]

Even with a two way portal, there's a bunch of ways to handle things:

The portal might have a trigger before transport occurs. That is, you step wholly into a nonspace within the portal and then when some outside trigger happens you are suddenly moved to within the destination portal. Rope tied to someone (or lowered into) the portal would be severed, you can step back before the transport happens and so forth. If the origin portal was under water, water would arrive at the destination in periodic splashes when the trigger occurs.

The portal might require a conscious, willing impetus to enter it (this one can be combined with many other portal rules). In this case a person who steps into a portal goes just fine, someone shoved into the portal might bounce off it or simply fall through to the other side as if it weren't there. Rope chucked in would bounce off. If the origin is underwater, the water won't pass through the portal etc.

The portal might specifically filter something. If, for example, you have a portal to the plane of fire in your house, you don't really want your living room to catch fire because of it. So fire might be either barred from passing the portal OR destroyed when it passes the portal, or transport might simply not work when someone attempts it with these items.

There might be a distance of space between the two ends of the portal. You might have to step into the portal and keep travelling some distance before emerging. Is the portal one-way at the entrance? Or the exit? Or all the way through?

There might be a time delay between entering the portal and emerging from it. You might throw in a rope and be unable to pull it back again for a minute.

The portal might use a duplication-at-destination mechanism. Normally, someone steps into the portal, is duplicated perfectly at the destination and destroyed at the point of leaving. Pulling back while the transport is ongoing might create clones, result in destruction of the transportee or cause a portal lockdown.

I'm sure there's more that I haven't thought of.

 

[Jhaelen]

1: rope goes back and forth, no problem
2: rope goes back and forth, no problem
3: rope cannot be pulled out until it gets to the half-way point, at which point the entire rope is pulled through faster than can be held, or it vanishes if it is tied-off. (this is a magic effect... once something is half-way through, it is all-the-way through... it is in an undefined state until it reaches the half-way point...)

This. Though I might decide that in case 3 the rope wears out and tears after a short delay.